Journal of Natural P&s Vol. 56, No. 7,pp. 1182-1183,July 1993
1182
l-PHENYLHEPTANE-l,5-DIONE FROM PHELLZNUS T R E M U L U S GERALD J. NELSON, DUANE P. ~~ATTHEEs, and DAVID E. LEWIS* Dqartnrent of Chemistry, South Dakota State Uniwrsity, Box 2202, Bmkings, South Dakota 5 7007-0896
ABS~~~~r.-l-Phenylheptane-l,5dione 111,which has not been previously reported as a natural product, has been isolated from Phellznus tremulus. This compound is the first naturally occurring phenylheptane oxidized in the 1 position and the first dione of this class of ~ n u a l products.
Phellinus tremulus Bondarzew et Borissov (Polyporaceae) is a fungus responsible for heart rot in aspen (Populus tremuloides)(1). The fungus, which is rich in melanin pigments (2), gradually renders the infected wood unsuitable for pulping due to low levels of essential carbohydrates (3). The phenylheptanes 2-5 have been isolated from the decayed heartwood of aspens infected with the organism (4). We report herein the isolation of the dione 1 directly from the fungus. This is the first report of this compound as a natural product, the first report of the isolation of any phenylheptane natural product directly from the fungus rather than the infected wood, the first report of a phenylheptanedione, and the first report of a phenylheptane oxidized at the 1 position isolated from this fungus. Compound 1 was isolated from the hexane-soluble fractions of the MeOH extract of Ph. tremulus by chromatog-
raphy on Si gel using EtOAc in hexane. Elution first afforded the known esters 613 and the phenylheptanone 3, after which the new phenylheptanedione 1 eluted as a pale yellow oil which crystallized on standing. Long-chain fatty acids similar to those isolated from Ph. tremulus occur in several species of fungus and plants, including Fomes zgniarius ( 5 ) , Agaricus bispwus (6), and pecans (Carya illinoensis) (7). The mass spectrum of the new natural product exhibited a molecular ion at mlz 204 and a base peak at mlz 105, consistent with the molecular formula as C13H1602and the presence of a C6H,COmoiety. The 'H (Table 1) and 13C n m r (Experimental) revealed the presence of two ketonic carbonylgroups (one ofwhich is conjugated), a monosubstituted aromatic ring, an isolated ethyl group, and a trimethylene group. The ir spectrum showed carbonyl absorptions at 1684and 1717 cm-'. These data clearly estab-
3 w 7 6
4'
5'
1 R=O, R'=H, R"=O 2 R=O, R'=OH, R"=H,
3 R=O, R'=H, R"=H, 4 R=H, OH; R ' = H , Rrr=H,
5
July 19937
Nelson et ai.:
1183
1-Phenylheptane-1J-dione
TABLE1. 'H-nmr S m t r a l Dat :200 MHz) for 1. Proton
Chemical Shift
Multiplicity t
J6.7
9 t t
d m
EXPERIMENTAL GENERAL EXPERIMENTAL PROCEDURES.Nmr spectra were obtained using a Varian Gemini 200 spectrometer at 200 MHz ('H) and 50 MHz (',C) using CDCI, solutions with TMS as standard. Ms were obtained using a Hewlett-Packard 5970 MSD gc-ms system containing a 30 m capillary column with a 5 % phenylsilicone/95% methylsilicone liquid phase with oven temperatures being programmed at 100' for 3 min, then ramped at lO'/min for 18 min; ionization was carried out at 70 eV. Ir spectra were recorded by diffuse reflectance from KBr using a BioRad FTS 60-A ir spectrophotometer. FUNGALm m u u . - P h . tremulus was collected in the Snake River State Forest in central Minnesota in April and May 1992. A voucher specimen is preserved in the Department of Chemistry, South Dakota State University, Brookings.
ISOLATION OF C O M p o W 1.-Dried fungus (11.3 kg) was extracted three times with MeOH (30 liters) for a week, and the combined extracts were evaporated under reduced pressure to yield 163 g of oil. The crude extract (67 g) was partitioned between H,O-CH,Cl, (1: 1) to yield 27 g of a CH,CI,-soluble fraction; further partitioning of this fraction between 10% H,O/MeOH and hexane yielded 11.0 g of a hexane-soluble fraction. This fraction (5.0 g) was subjected to cc on Si gel (125 g adsorbent; EtOAc in hexane eluent). The material eluted from the columnwith 20% EtOAc in hexane was subjected to preparative tlc (Si gel,
=7.3 5
7.35 7.14 7.14, J,,,=6.96 J2,,=6.96 J2f,3t=J1t,6f=7.40 J6.7=
J3,4=
toft
lished the constitution of the natural product as 1.Comparison of the observed 'H-nmr spectral data with those published (8) for 1 confirmed the assignments.
Coupling Constants
-
20% EtOAdhexane); the fractions of R, 0.6-0.7 were subjected to preparative hplc (Si gel, 10% EtOAc/hexane) and afforded 1as a pale yellow oil (18mg) which crystallized on standing. Recrysrallization from C,H,/hexane afforded 1 as a white crystalline solid: mp 62-64'; Y max cm-' (KBr) 3068, 2970, 2942, 1717, 1684, 1456, 1387, 1279,1218,1122,755,706 cm-'; Amaxnm(1og E) (EcOH) 238 (4.04); 13C n m r 6 211.8 (C-3), 200.2 (C-l), 137.5 (C-l'), 133.5 (C-4'), 129.0, 128.5 (C-2', C-3'), 41.7,37.8 (C-2, C-4), 36.0 (C6), 18.5 (C-3),8.0(C-7)ppm;'HnmrseeTable 1; eims mlz (%) {M+204 (9), 175 (8),148 (4), 147 (21), 120 (29), 105 (100),77 (46).
LITERATURE CITED 1.
2.
3.
4. 5.
6.
7. 8.
W.A. Sinclair,H.H. Lyon, and W.T. Johnson, "Diseases of Trees and Shrubs," Comstock Publishing Associates, Ithaca, NY, 1987, pp. 342-343. A.A. Malama, N.I. Fedorov, S.V. Lomakina, and F. Kovalenko, Biol. Nauki (Moscoru), 1 8 , 93 (1975); Chem. Abstr., 83,45582 (1975). N.I. Bol'shova, in: "Mikrorg. Nizshie Rast.Razrushiteli Mater. Izdelii." Ed. by M.V. Gorlenko, Izd. Nauka SSSR, Moscow, 1979, pp. 168-173; Chem. Abstr., 92, 199969a (1979). K.Serck-Hanssen and C. Wikstrom, Phytochemistry, 17,1678 (1978). T. Rezanka and P. Mares, J. Chmmatogr., 409, 390 (1987). B.K.Kim, M.H. Lee,and M.J. Shim, Hanguk Kyunbakhoe Chi, 6, 5 (1978); Chem. Abstr., 91, 35750a (1979). S.D. Senter and R.J. Horvat, J. FwdSci., 43, 1614 (1978). H. Ahlbrecht, M. Dietz, and L Weber, Synthesis, 251 (1987).
Receiwd 26 October 1992
